Reflective and transflective liquid crystal display devices and a fabricating method thereof

ABSTRACT

An array substrate for a transflective liquid crystal display device which includes a substrate having a display region and a boundary region; a gate line disposed on the substrate; a first insulating layer disposed on the gate line; a data line disposed on the first insulating layer, the data line crossing the gate line and defining a pixel region with the gate line; a thin film transistor connected to the gate line and the data line; a second insulating layer disposed on the thin film transistor; a reflective plate disposed on the second insulating layer at the display region, the reflective plate being extended to the boundary region and having a transmission hole in the pixel region; a third insulating layer disposed on the reflective plate; and a pixel electrode disposed on the third insulating layer at the pixel region, the pixel electrode being connected to the thin film transistor.

This application is a divisional of U.S. application Ser. No. 10/152,030filed on May 22, 2002 now U.S. Pat. No. 6,970,217, now allowed, whichclaims the benefit of Korean Patent Application No. 2001-28120, filed onMay 22, 2001 in Korea. Both prior applications are hereby incorporatedby reference for all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to reflective and transflective liquidcrystal display (LCD) devices and more particularly, to reflective andtransflective LCD devices using a dispensing method and a fabricatingmethod thereof.

2. Discussion of the Related Art

Generally, liquid crystal display (LCD) devices include upper and lowersubstrates, where color filters and thin film transistors (TFTs) arerespectively disposed. A liquid crystal layer is interposed between theupper substrate and the lower substrate. Transmittance of the LCDdevices is controlled by applying a voltage to common electrodes andpixel electrodes so that characters and images are displayed with alight shutter effect.

A fabrication process of a liquid crystal cell will be explainedbriefly.

After the upper and lower substrates are aligned and attached so thatthe surfaces of the common electrodes and pixel electrodes face eachother, the liquid crystal material is injected between the substratesthrough an injection hole and the injection hole is then sealed. Apolarizer is then attached to each outer surface of the upper and lowersubstrates.

The fabrication process of the liquid crystal cell seldom includesrepeated steps compared with the fabrication processes of the TFT andthe color filter. The process includes forming an orientation film,forming a cell gap and cutting the cell.

FIG. 1 is a flow chart illustrating a conventional fabrication processof a liquid crystal cell.

In step st1, a lower substrate is prepared by forming an array of TFTsand pixel electrodes on the lower substrate.

In step st2, an orientation film is formed on the lower substrate.Formation of the orientation film includes depositing a polymeric thinfilm on the substrate and subsequently performing a uniform rubbingprocess. The rubbing process determines an initial alignment directionand supplies the normal operation of the liquid crystal layer and theuniform display characteristic of the LCD device. Typically, an organicmaterial of the polyamide series is used as the orientation film. Therubbing method includes rubbing the orientation film in a specificdirection with a rubbing cloth, thereby aligning the liquid crystalmolecules along or in the rubbing direction.

In step st3, a seal pattern is formed on the lower substrate. In theliquid crystal cell, the seal pattern serves two functions: forming agap for the injection of the liquid crystal material and confining theinjected liquid crystal material. The seal patterning process forms adesired pattern by the application of a thermosetting plastic. Ascreen-printing method using a screen mask is typically used for thisprocess.

In step st4, a spacer is sprayed on the lower substrate. The size of thespacer used in the liquid crystal cell maintains a precise and uniformgap between the upper and lower substrates. Accordingly, the spacers areuniformly sprayed on the lower substrate. The spacer spray method can bedivided into two different types: a wet spray method that involvesspraying a mixture of alcohol and spacer material and a dry spray methodthat involves spraying spacer material alone. Furthermore, the dry spraymethod can be sub-divided into two different types: an electrostaticspray method that uses electrostatic force, and a non-electric spraymethod that uses gas pressure. Since the liquid crystal cell structureis susceptible to damage from static electricity, the non-electricmethod is widely used.

In step st5, the upper and lower substrates are aligned and attached.The alignment margin between the upper and lower substrates isdetermined by the device design, and accuracy within a few micrometersis generally required. If the alignment margin is exceeded, the liquidcrystal cell will not operate adequately due to light leakage.

In step st6, the attached liquid crystal substrate is divided into unitcells. Generally, a plurality of unit cells are formed on a large sizedglass substrate and then divided through a cutting process. In thefabrication process of the initial LCD devices, the unit cells areseparated after simultaneous injection of the liquid crystal materialinto the unit cells. However, injection of liquid crystal material iscommonly performed after a large sized liquid crystal substrate is cutinto unit cells due to an increase in the cell size. The cell cuttingprocess includes a scribe process that forms cutting lines on a surfaceof the substrate using a diamond pen, the hardness of which is higherthan that of the glass substrate, and a breaking process that dividesthe substrate by force.

In step st7, a liquid crystal material is injected into the unit cells.The unit cell has a size of several hundred square centimeters with agap of several micrometers. Accordingly, a vacuum injection method usingpressure difference between the interior and exterior of the unit cellis commonly used as an effective injection method.

The injection method of liquid crystal material is classified into a dipmethod or a contact method. In the dip method, the injection hole isdipped into a liquid crystal tank under a vacuum state and the liquidcrystal material is injected due to a pressure difference betweeninterior and exterior of an LCD panel. In the contact method, theinjection hole contacts the surface of the liquid crystal material inthe liquid crystal tank. However, the injection method using a pressuredifference under a vacuum takes a long period of time and also theinjection hole may become contaminated.

To solve the above problems, a dispensing method is suggested. In thedispensing method, a sealant is printed at a boundary of a plurality ofcells on an array substrate and then the liquid crystal material issufficiently dropped in a region defined by the sealant using a meanssuch as a dispenser. A process time is reduced and the production yieldis dramatically improved because the liquid crystal layer is formed inthe LCD panel in a short period of time.

FIGS. 2A to 2F are schematic plan views and cross-sectional viewsshowing the fabricating process of a liquid crystal cell.

In FIGS. 2A and 2B, a first substrate 2 having a plurality of liquidcrystal cells “A” is provided. The first substrate 2 has a sub-colorfilter corresponding to a pixel electrode of a second substrate and ablack matrix corresponding to a region between the adjacent pixelelectrodes.

In FIGS. 2C and 2D, a sealant 6 is printed on a second substrate 4 atregions corresponding to the boundary of each liquid crystal cell “A.”The second substrate 4 has an array line, a pixel electrode and aswitching device, i.e., a thin film transistor (TFT). Next, a liquidcrystal layer is formed at an interior 8 of the sealant with adispenser.

In FIGS. 2E and 2F, the first substrate 2 is attached to the secondsubstrate 4 having the liquid crystal layer to form a liquid crystalpanel 10. Then a shielding mask 12 is disposed over the liquid crystalpanel 10. The shielding mask 12 includes a transmission region “B” and ashield region “C.” The transmission region “B” corresponds to thesealant 6 of the liquid crystal panel 10 and the shield region “C”corresponds to the interior of the sealant 6, i.e., a display area “D”of the liquid crystal panel 10. The display area “D” is shielded toprevent a channel of the TFT from being exposed to ultraviolet (UV)light during the hardening process of the sealant. Even though the firstsubstrate has the black matrix corresponding to the TFT, the incidentlight may be scattered by a reflective plate and influence the channel.Accordingly, the shielding mask should be used for preventing thisinfluence.

After hardening the sealant 6 with UV light, the first and secondsubstrates 2 and 4 are completely attached through a hot press process.The attached substrates are then cut into a plurality of unit cells.

However, when the dispensing method is used for the forming process ofthe liquid crystal layer, the UV light should be irradiated to thesealant for hardening. Therefore, the black matrix should not be formedon the first substrate at a region corresponding to the sealant.Therefore, to prevent the pixel region from being exposed to UV light,larger margins are necessary when a boundary of the liquid crystal panelis designed.

FIG. 3 is a schematic plan view of a conventional transflective LCDdevice where a liquid crystal layer is formed through the dispensingmethod and FIG. 4 is a cross-sectional view taken along a line IV—IV ofFIG. 3.

In FIGS. 3 and 4, a second substrate 14, referred to as an arraysubstrate, for a transflective LCD device has a pixel region “P”including a transmissive portion “E” and a reflective portion “F.” Thetransmissive portion “E” and the reflective portion “F” have atransflective electrode formed by overlapping a transparent electrode 16and a reflective electrode 20 having a transmissive hole 18. The pixelregion “P” is defined by a gate line 22 and a data line 24 crossing thegate line 22. A gate pad 23 and a data pad (not shown) having a specificarea are disposed at an end of the gate line 22 and the data line 24,respectively. A TFT “T” including a gate electrode 26, an active layer32, and source and drain electrodes 28 and 30 are connected to the gateand data lines 22 and 24.

A black matrix 36 and a color filter 37 are formed on a first substrate34, referred to as a color filter substrate, said first substratecorresponding to the second substrate 14. The black matrix 36corresponding to the TFT “T” of the second substrate 14 shields anactive layer 32 from incident light. Since a sealant 6 is an UV curableresin, the sealant should be irradiated by UV light and thus the blackmatrix 36 should not be formed over the sealant 6.

However, in the transflective LCD panel of the above structure, sincethe black matrix is formed on the first substrate, the aperture ratiodecreases. Moreover, since the black matrix is not formed at a regioncorresponding to the sealant, larger margins are necessary to protectthe display region when a boundary of the liquid crystal panel isdesigned. Therefore, it is difficult to apply the transflective LCDpanel of the above structure to a compact product such as a mobilephone. Further, the fabrication cost are increased due to the use of anadditional shielding mask. These problems do not occur only in atransflective LCD device but also in a reflective LCD device.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to an array substrate fora liquid crystal display device that substantially obviates one or moreof problems created due to the limitations and disadvantages of therelated art.

An advantage of the present invention is to provide an array substratefor a transflective or reflective liquid crystal display device in whichthe reflective plate is extended to the boundary of the display regionso that an additional shielding mask for hardening and a black mask arenot necessary.

Additional features and advantages of the present invention will be setforth in the description which follows, and in part will be apparentfrom the description, or may be learned by the practice of the presentinvention. The objectives and other advantages of the present inventionwill be realized and attained by the structure particularly pointed outin the written description and claims hereof as well as the appendeddrawings.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, an arraysubstrate for a transflective liquid crystal display device is providedwhich includes: a substrate having a display region and a boundaryregion; a gate line disposed on the substrate; a first insulating layerdisposed on the gate line; a data line disposed on the first insulatinglayer, the data line crossing the gate line and defining a pixel regionwith the gate line; a thin film transistor connected to the gate lineand the data line; a second insulating layer disposed on the thin filmtransistor; a reflective plate disposed on the second insulating layerat the display region, the reflective plate being extended to theboundary region and having a transmission hole in the pixel region; athird insulating layer disposed on the reflective plate; and a pixelelectrode disposed on the third insulating layer at the pixel region,the pixel electrode being connected to the thin film transistor.

In another aspect of the present invention, the transflective liquidcrystal display device includes: first and second substrates facing eachother and spaced apart from each other, the second substrate having adisplay region and a boundary region; a common electrode disposed on aninner surface of the first substrate; a gate line disposed on an innersurface of the second substrate; a first insulating layer disposed onthe gate line; a data line disposed on the first insulating layer, thedata line crossing the gate line and defining a pixel region with thegate line; a thin film transistor connected to the gate line and thedata line; a second insulating layer disposed on the thin filmtransistor; a reflective plate disposed on the second insulating layerat the display region, the reflective plate being extended to theboundary region and having a transmission hole in the pixel region; athird insulating layer disposed on the reflective plate; a pixelelectrode disposed on the third insulating layer in the pixel region,the pixel electrode being connected to the thin film transistor; asealant disposed over the reflective plate at the boundary region; and aliquid crystal layer interposed between the common and pixel electrodes.

In a further aspect of the present invention, a fabricating method for atransflective liquid crystal display device includes: forming a commonelectrode on a first substrate; forming a gate line on a secondsubstrate having a display region and a boundary region; forming a firstinsulating layer on the gate line; forming a data line on the firstinsulating layer, the data line crossing the gate line and defining apixel region with the gate line; forming a thin film transistorconnected to the gate line and the data line; forming a secondinsulating layer on the thin film transistor; forming a reflective plateon the second insulating layer at the display region, the reflectiveplate being extended to the boundary region and having a transmissionhole at the pixel region; forming a third insulating layer on thereflective plate; forming a pixel electrode on the third insulatinglayer in the pixel region, the pixel electrode being connected to thethin film transistor; forming a sealant over the reflective plate at theboundary region; dispensing liquid crystal molecules to the interior ofthe sealant; attaching the first and second substrates; and hardeningthe sealant by irradiating light.

In yet another aspect of the present invention, an array substrate for areflective liquid crystal display device includes: a substrate having adisplay region and a boundary region; a gate line disposed on thesubstrate; a first insulating layer disposed on the gate line; a dataline disposed on the first insulating layer, the data line crossing thegate line and defining a pixel region with the gate line; a thin filmtransistor connected to the gate line and the data line; a secondinsulating layer disposed on the thin film transistor; a reflectiveplate disposed on the second insulating layer at the display region, thereflective plate being extended to the boundary region and having anopen portion over the thin film transistor; a third insulating layerdisposed on the reflective plate; and a pixel electrode disposed on thethird insulating layer at the pixel region, the pixel electrode beingconnected to the thin film transistor through the open portion.

Still another aspect of the present invention, the reflective liquidcrystal display device includes: first and second substrates facing eachother and spaced apart from each other, the second substrate having adisplay region and a boundary region; a common electrode disposed on aninner surface of the first substrate; a gate line disposed on an innersurface of the second substrate; a first insulating layer disposed onthe gate line; a data line disposed on the first insulating layer, thedata line crossing the gate line and defining a pixel region with thegate line; a thin film transistor connected to the gate line and thedata line; a second insulating layer disposed on the thin filmtransistor; a reflective plate disposed on the second insulating layerat the display region, the reflective plate being extended to theboundary region and having an open portion over the thin filmtransistor; a third insulating layer disposed on the reflective plate; apixel electrode disposed on the third insulating layer at the pixelregion, the pixel electrode being connected to the thin film transistorthrough the open portion; a sealant provided over the reflective plateat the boundary region; and a liquid crystal layer interposed betweenthe common and pixel electrodes.

In still a further aspect of the present invention, the fabricatingmethod of a reflective liquid crystal display device includes: forming acommon electrode on a first substrate; forming a gate line on a secondsubstrate having a display region and a boundary region; forming a firstinsulating layer on the gate line; forming a data line on the firstinsulating layer, the data line crossing the gate line and defining apixel region with the gate line; forming a thin film transistorconnected to the gate line and the data line; forming a secondinsulating layer on the thin film transistor; forming a reflective plateon the second insulating layer at the display region, the reflectiveplate being extended to the boundary region and having an open portionover the thin film transistor; forming a third insulating layer on thereflective plate; forming a pixel electrode on the third insulatinglayer at the pixel region, the pixel electrode being connected to thethin film transistor through the open portion; forming a sealant overthe reflective plate at the boundary region; dispensing liquid crystalmolecules to the interior of the sealant; attaching the first and secondsubstrates; and hardening the sealant by irradiating light.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide a further explanation of the present invention asclaimed, and should not be considered as limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the present invention and are incorporated in andconstitute a part of this specification, illustrate embodiments of theinvention and together with the description serve to explain theprinciples of the present invention, and wherein:

FIG. 1 is a flow chart illustrating a conventional fabrication processof a liquid crystal cell;

FIGS. 2A to 2F are schematic plan views and cross-sectional viewsshowing a fabricating process of a liquid crystal cell;

FIG. 3 is a schematic plan view of a conventional transflective LCDdevice wherein a liquid crystal layer is formed through the dispensingmethod;

FIG. 4 is a cross-sectional view taken along a line IV—IV of FIG. 3;FIG. 4 illustrates the structure of a mask slit and a light intensityprofile that results from the mask structure according to the relatedart;

FIG. 5 is a plan view of an array substrate for a transflective liquidcrystal display device according to a first embodiment of the presentinvention;

FIGS. 6A to 6D are schematic cross-sectional views showing the steps ofa fabricating process of an array substrate, taken along line VI—VI ofFIG. 5;

FIGS. 7A to 7C are schematic cross-sectional views showing the steps ofa fabricating process of a transflective LCD device according to thefirst embodiment of the present invention;

FIG. 8 is a schematic plan view of an array substrate for a reflectiveliquid crystal display device according to a second embodiment of thepresent invention;

FIGS. 9A to 9D are schematic cross-sectional views showing the steps ofa fabricating process of an array substrate and taken along a line IX—IXof FIG. 8; and

FIGS. 10A to 10C are schematic cross-sectional views showing the stepsof a fabricating process of a reflective LCD device according to asecond embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the illustrated embodiments ofthe present invention, as shown in the accompanying drawings.

FIG. 5 is a plan view of an array substrate for a transflective liquidcrystal display device according to the first embodiment of the presentinvention.

In FIG. 5, a transflective electrode of an array substrate 100 for atransflective LCD device is composed of transparent and reflectiveelectrodes 130 and 120. Here, the reflective electrode 120 is areflective plate that is not connected to a drain electrode 112. Sincethe reflective plate 120 is electrically floating, i.e., insulated froman electrical source, the reflective plate 120 may be extended over aTFT “T” of the array substrate 100 to be formed on the entire surface ofthe array substrate 100.

FIGS. 6A to 6C are schematic, cross-sectional views showing the steps offabricating process of an array substrate, taken along a line VI—VI ofFIG. 5.

In FIG. 6A, a gate electrode 102 of a single metal layer such asaluminum (Al), aluminum neodymium (AlNd), tungsten (W), chromium (Cr) ormolybdenum (Mo), or a double metal layer such as Al/Cr or Al/Mo isformed on a substrate 100. Since material for the gate electrode 102 isimportant to operation of an LCD device, aluminum of low resistance hasbeen widely used to reduce RC delay. However, since for pure aluminum,corrosion resistance to chemical solutions is low and hillock readilyforms at high temperature, an alloy or a double layer is usually adoptedfor the aluminum line.

A first insulating layer 104 of inorganic insulating material such assilicon nitride (SiNx) or silicon oxide (SiO₂), or an organic insulatingmaterial such as benzocyclobutene (BCB) or an acrylic resin is formed onthe gate electrode 102. A semiconductor layer including an active layer116 of amorphous silicon and an ohmic contact layer 117 of dopedamorphous silicon is formed on the first insulating layer 104 over thegate electrode 102. Source and drain electrodes 110 and 112, and a dataline 115 of conductive metallic material are formed on the ohmic contactlayer 117. The data line 115 is perpendicularly extended from the sourceelectrode 110.

In FIG. 6B, a second insulating layer 119 is formed on the entiresurface of the substrate 100 by depositing thereon one of the organicinsulating materials, e.g., BCB and/or an acrylic resin. Next, a firstcontact hole 121 corresponding to the drain electrode 112 and a groove122 corresponding to a transmissive portion of a pixel region are formedby etching the second insulating layer 119. Even though the groove 122is formed to reduce a color shift by making light paths of reflectiveand transmissive portions equal, the groove 122 is not essential and maybe omitted. Next, a reflective plate 120 having an open portion 124 anda transmission hole 126 is formed on the second insulating layer 119through depositing and patterning one of metal groups including Al andAl alloys such as AlNd. The open portion 124 and the transmission hole126 correspond to the drain electrode 112 and the groove 122,respectively.

In FIG. 6C, a third insulating layer 128 is formed on an entire surfaceof the substrate 100 by depositing one of the inorganic insulatingmaterials, such as SiNx and SiO₂. Portions corresponding to the openportion 124 and the transmission hole 126 are etched to expose the drainelectrode 112 and the substrate of the transmissive portion,respectively. Even though the contact hole and the groove are formedthrough two mask processes for the second and third insulating layers,they may be formed through only one mask process after forming the thirdinsulating layer, in another embodiment.

In FIG. 6D, a pixel electrode 130 connected to the drain electrode 112is formed in the pixel region by depositing and patterning one of thetransparent conductive metal groups, such as indium tin oxide (ITO)and/or indium zinc oxide (IZO).

FIGS. 7A to 7C are schematic cross-sectional views showing a fabricatingprocess of a transflective LCD device according to the first embodimentof the present invention.

In FIG. 7A, a light curable sealant 135 is formed at the boundary regionof an array substrate 144 provided through the process steps of FIGS. 6Ato 6D. The sealant 135 is formed adjacent to a driving part at theboundary of the array substrate 114 and disposed between a signal line(the gate or data lines) and a pad 137 at an end of the gate or datalines.

In FIG. 7B, liquid crystal molecules 138 are dispensed interiorly of thesealant 135 using a dispenser. Since more liquid crystal molecules canfill the interior in a short period of time through the dispensingmethod, the process time can be substantially reduced.

In FIG. 7C, a color filter substrate 146 is attached to the arraysubstrate 144 to form a liquid crystal panel 132. A color filter layer136, a planarization layer 140 and a common electrode 142 aresubsequently formed on a substrate 134 to produce the color filtersubstrate 146. If ultraviolet (UV) light is irradiated from an upperpart of the color filter substrate 146, the sealant 135 at the boundaryof the liquid crystal panel 132 is hardened so that the attachment ofthe color filter substrate 146 and the array substrate 144 becomesfirmer.

As a result, the color filter substrate 146 has only color filter layer136 in the transflective LCD device 132 according to the firstembodiment of the present invention. Even though the black matrixcorresponding to a TFT “T” of the array substrate 144 is not formed onthe color filter substrate 146, the reflective plate 120 of the arraysubstrate 144 may shield the TFT “T.” Therefore, the aperture ratio isimproved. Moreover, when the sealant 135 is hardened with the UV light,the display region including the pixel region is not exposed to the UVlight without an additional shield mask.

FIG. 8 is a schematic plan view of an array substrate for a reflectiveliquid crystal display device according to a second embodiment of thepresent invention.

In FIG. 8, a reflective plate 220 and a transparent electrode 226 areformed on an array substrate 200. The reflective plate 220 is extendedto a region “G,” a boundary region of a liquid crystal panel, where asealant (not shown) is formed. The transparent electrode 226 isconnected to each drain electrode 214 to drive each pixel region “P”independently. A source electrode 212 is spaced apart from the drainelectrode 214 and extended from a data line 210. A gate electrode 202 isconnected to a gate line 203 and a gate pad 207 is formed at an end ofthe gate line 203.

FIGS. 9A to 9D are schematic cross-sectional views showing a fabricatingprocess of an array substrate taken along a line IX—IX of FIG. 8. Sincethe process of FIGS. 9A to 9C is similar to that of FIGS. 6A to 6C,FIGS. 9A to 9C will be only briefly explained.

In FIG. 9A, a gate electrode 202 of a single metal layer such asaluminum (Al), aluminum neodymium (AlNd), tungsten (W), chromium (Cr) ormolybdenum (Mo), or a double metal layer such as Al/Cr or Al/Mo isformed on a substrate 200. A first insulating layer 204 of inorganicinsulating material such as silicon nitride (SiNx) or silicon oxide(SiO₂), or an organic insulating material such as benzocyclobutene (BCB)and/or an acrylic resin is formed on the gate electrode 202. Asemiconductor layer including an active layer 206 of amorphous siliconand an ohmic contact layer 208 of doped amorphous silicon is formed onthe first insulating layer 204 over the gate electrode 202. Source anddrain electrodes 212 and 214, and a data line 210 of conductive metallicmaterial are formed on the ohmic contact layer 208.

In FIG. 9B, a second insulating layer 216 is formed on the entiresurface of the substrate 200 by depositing thereon an organic insulatingmaterial, such as BCB and/or an acrylic resin. Next, a first contacthole 218 corresponding to the drain electrode 214 is formed by etchingthe second insulating layer 216. Next, a reflective plate 220 having anopen portion 219 is formed on the second insulating layer 216 bydepositing and patterning one of a metal group, such as Al and/or an Alalloy such as AlNd. The open portion 219 corresponds to the firstcontact hole 218. The reflective plate 220 is extended to a region wherea sealant is printed in the next process. Since the reflective plate 220is formed on an entire surface of the pixel region “P,” a correspondingTFT “T” is shielded from light. Moreover, since the reflective plate 220is not connected to the drain electrode 214, an additional transparentelectrode to drive the pixel region “P” independently is formed.

In FIG. 9C, a third insulating layer 224 is formed on the entire surfaceof the substrate 200 by depositing thereon an inorganic insulatingmaterial, such as SiNx and/or SiO₂. A second contact hole 226corresponding to the open portion 219 is formed to expose the drainelectrode 214.

In FIG. 9D, a pixel electrode 228 connected to the drain electrode 214is formed on the third insulating layer 224 in the pixel region “P” bydepositing and patterning one of a transparent conductive metal groupincluding ITO and IZO.

FIGS. 10A to 10C are schematic cross-sectional views showing afabricating process of a reflective LCD device according to a secondembodiment of the present invention.

In FIG. 10A, a light curable sealant 232 is formed at the boundaryregion of an array substrate 240 produced through the process steps ofFIGS. 9A to 9D. The sealant 232 is formed adjacent to a driving part atthe boundary of the array substrate 240 and disposed between a signalline (the gate or data lines) and a pad 207 at an end of the gate ordata lines.

In FIG. 10B, liquid crystal molecules 242 are dispensed interiorly ofthe sealant 232 by using a dispenser. As mentioned, since more liquidcrystal molecules can fill the interior in a short period of timethrough the dispensing method, the process time can be substantiallyreduced.

In FIG. 10C, a color filter substrate 250 is attached to the arraysubstrate 240 to form the liquid crystal panel 233. A color filter layer236, a planarization layer 246 and a common electrode 248 aresubsequently formed on a substrate 234 to produce the color filtersubstrate 250. The color filter layer 236 of the color filter substrate250 is formed only at that portion corresponding to the pixel electrode228 of the array substrate 240. If ultraviolet (UV) light is irradiatedfrom an upper part of the color filter substrate 250, the sealant 232 atthe boundary of the liquid crystal panel 233 is hardened so that theattachment of the color filter substrate 250 and the array substrate 240becomes firmer.

In the second embodiment, the reflective plate 220 does not include atransmission hole corresponding to the pixel region due to thereflective LCD device. Further, the reflective plate 220 is formed onthe entire surface of a display region including the pixel region andextended to the boundary region including the sealant, i.e., a regionadjacent to the pad 207 so that an additional black matrix over the TFTand shield mask are not necessary.

The transflective or reflective LCD device according to the presentinvention has a number of advantages.

First, since a reflective plate is formed to cover a TFT of an arraysubstrate and extended to the sealant, a black matrix of a color filtersubstrate is not necessary and a shield mask screening the pixel regionis not necessary since the sealant is hardened with UV light. Therefore,the fabricating process is simplified and a fabrication cost is reduced.

Second, since the black matrix is not formed, a margin for misalignmentneed not be considered when designing the array substrate. Therefore, itis readily applicable to a small size LCD device.

Third, since the black matrix is not formed, the aperture ratio isimproved.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the fabrication andapplication of the present invention without departing from the spiritor scope of the invention. Thus, it is intended that the presentinvention cover the modifications and variations thereof provided theycome within the scope of the appended claims and their equivalents.

1. A fabricating method of a transflective liquid crystal displaydevice, comprising: forming a common electrode on a first substrate;forming a gate line on a second substrate having a display region and aboundary region; forming a first insulating layer on the gate line;forming a data line on the first insulating layer, the data linecrossing the gate line and defining a pixel region with the gate line;forming a thin film transistor connected to the gate line and the dataline; forming a second insulating layer on the thin film transistor;forming a reflective plate on the second insulating layer at the displayregion, the reflective plate being extended to the boundary region andhaving a transmission hole at the pixel region; forming a thirdinsulating layer on the reflective plate; forming a pixel electrode onthe third insulating layer at the pixel region, the pixel electrodebeing connected to the thin film transistor; forming a sealant over thereflective plate at the boundary region; dispensing liquid crystalmolecules interiorly of the sealant; attaching the first and secondsubstrates; and hardening the sealant with irradiating light.
 2. Themethod according to claim 1, further comprising forming a color filterlayer between the first substrate and the common electrode.
 3. Afabricating method of a reflective liquid crystal display device,comprising: forming a common electrode on a first substrate; forming agate line on a second substrate having a display region and a boundaryregion; forming a first insulating layer on the gate line; forming adata line on the first insulating layer, the data line crossing the gateline and defining a pixel region with the gate line; forming a thin filmtransistor connected to the gate line and the data line; forming asecond insulating layer on the thin film transistor; forming areflective plate on the second insulating layer at the display region,the reflective plate being extended to the boundary region and having anopen portion over the thin film transistor; forming a third insulatinglayer on the reflective plate; forming a pixel electrode on the thirdinsulating layer at the pixel region, the pixel electrode beingconnected to the thin film transistor through the open portion; forminga sealant over the reflective plate at the boundary region; dispensingliquid crystal molecules interiorly of the sealant; attaching the firstand second substrates; and hardening the sealant with irradiating light.4. The method according to claim 3, further comprising forming a colorfilter layer between the first substrate and the common electrode.